This neat and easy "trick" allows you to add 9 or 8 to any number with ease!
For example, to solve 9 + 7, imagine that 9 wants to be 10, so it gets "one" from the seven, leaving seven to become only six. So the addition 9 + 7 is changed to the sum 10 + 6 which is super easy to solve.
We can also use a similar strategy in sums with 8. For example to solve 8 + 5, imagine that 8 wants to be 10, so it gets two from the 5, which then becomes only 3. So the sum 8 + 5 becomes 10 + 3, which is an easy sum to solve.
First and second graders can use these mental math techniques to help their load of memorization of addition facts.
This same "trick" or thought pattern also works with two-digit numbers ending in 9, three-digit numbers ending in 99, and so on.
If you cannot see the video above, click here for an alternative video player.
Add a 2-digit number and a single-digit number mentally - no regrouping — video lesson
Math Mammoth Grade 1 curriculum
Math Mammoth TourConfused about the different options? Take a virtual email tour around Math Mammoth! You'll receive: An initial email to download your GIFT of over 400 free worksheets and sample pages from my books. Six other "TOURSTOP" emails that explain the important things and commonly asked questions concerning Math Mammoth curriculum. (Find out the differences between all these different-colored series!)This way, you'll have time to digest the information over one or two weeks, plus an opportunity to ask me personally about the curriculum. A monthly collection of math teaching tips & Math Mammoth updates (unsubscribe any time) We respect your email privacy.
Note: You will FIRST get an email that asks you to confirm your email address. If you cannot find this confirmation email, please check your SPAM/JUNK folder. |
"Mini" Math Teaching CourseThis is a little "virtual" 2-week course, where you will receive emails on important topics on teaching math, including:
- How to help a student who is behind You will also receive: A GIFT of over 400 free worksheets and sample pages from my books right in the very beginning. A monthly collection of math teaching tips & Math Mammoth updates (unsubscribe any time)We respect your email privacy.
Note: You will FIRST get an email that asks you to confirm your email address. If you cannot find this confirmation email, please check your SPAM/JUNK folder. |
Maria's Math TipsEnter your email to receive math teaching tips, resources, Math Mammoth news & sales, humor, and more! I tend to send out these tips about once monthly, near the beginning of the month, but occasionally you may hear from me twice per month (and sometimes less often). Peek at the previous tips here. You will also receive:
We respect your email privacy.
|